The Best Mistake
by YuriAllDahWay
Summary: In which Kumiko and Reina find themselves realizing their feelings for one another after a certain brunette messes up...again. Birthday gift for a friend (Happy birthday, you Sensitive Soybean).


**AN: A gift to my friend for her birthday. She complains about the lack of updates for KumiRei on here so I decided to indulge her craving for band gays. I hope you enjoy it too. It's been a while since I last wrote angst (is this even considered angst?), so bear with this. I never would have thought I would write this much for a oneshot, to be honest. First time for everything.**

 **And for you, Ranelle, happy fuckin' birthday.**

 **Now I can cry over Negitoro.**

* * *

It was a fairly normal day. Or, at least, that's what Reina Kousaka liked to believe.

It was summertime, and the ring of cicadas filled the humid air. Reina's hair was up in a ponytail, the dark color of it attracting far too much heat for her liking. Even with sitting on a bench underneath a large tree that blocked most of the sun's rays, Reina still found sweat rolling down her neck and down her back, drenching the back of her school uniform. She frowned; it was not a pleasant feeling.

A very unladylike groan sounded beside her.

Reina turned to her side, smiling at her companion whom was slouching against the back of the bench.

 _At least she makes everything somewhat better,_ Reina mused, watching the way her friend's brown eyes fluttered to a close. Reina took this chance and closed the distance so that they were nose-to-nose, one of Reina's bangs falling from behind her ear to barely flutter against her friend's cheek.

"Kumiko," Reina barely said, her voice just above a whisper. The brunette opened her eyes in a flash, surprise and shock plastered on her face.

"Guah!" Kumiko scrambled to the far end of the bench, but forgot that her euphonium was standing bell-down on the bench. She crashed into it and both the girl and the instrument were sent toppling down to the floor. There was the distinct sound of metal hitting concrete, and Reina cringed instinctively; she was positive that there was now a dent in Kumiko's euphonium.

"No, my baby!" Kumiko cried out, cradling her instrument close to her body. With watery eyes, she stared up at Reina.

Reina stared back with disapproving eyes. But then the serious mask she wore broke into a smile and she started laughing, genuine laughter that only Kumiko could draw out of her.

"You're dumb," the black-haired girl said, "Now you have to pay the school for fixing your euph now."

Kumiko gave a strained cry as she hefted herself and her instrument off of the ground. "N-no I don't."

"There's a huge dent on the side."

The brunette took a quick glance at her euphonium, and her eyes widened at the sight of the dent.

"Oh my God," Kumiko cried out, placing her hand over the dent. It was slightly larger than her hand, and Reina could see Kumiko calculating the cost of repairs. Kumiko looked like she was going to cry.

Reina just could not help laughing at her friend's expense—it was far too entertaining.

"This is just as bad as what happened earlier today," Kumiko pouted, patting her euphonium gingerly, as if it could fall apart at any moment.

"What happened?" Reina asked, turning her head to the side.

The brunette quickly covered her mouth with a little "mmf!" before staring at Reina with wide eyes—Reina felt herself admiring such a cute view. She also noticed that Kumiko's cheeks were now a dusty pink; whether it was from the heat or embarrassment, Reina did not know.

"Well, uh," Kumiko started, "Shuuichi—"

"Tsukamoto? The trombonist?"

"Uh, yeah. Him. He—"

"He?" Reina could feel the joy from earlier dissipating quickly.

"You're not going to let me finish a sentence are you—"

"He did _what_ , Kumiko?" Reina's tone of voice was steady and straight-to-the-point, just the way she wanted Kumiko to answer. The brunette's eyes flitted to and fro with nervous energy. Reina, on the other hand, was feeling impatient; she felt as if time were moving at a snail's pace.

"He asked me…." Kumiko waited a bit, obviously waiting for Reina's interjection. However nothing came, and Reina stared at her friend with an unsettling gaze. "He asked me to be his girlfriend."

That struck a nerve in Reina.

"Why?"

"He told me he always had feelings I guess—"

"What did you say?"

Kumiko blinked several times, seemingly getting lost due to Reina's constant interjections. Reina, however, could feel her impatience rising.

"What did I say?"

"Yes."

"Well, uh," Kumiko's face turned into a frown, then a grimace, and then she finally let out a loud groan. "He asked me on a date—"

"And?" Reina asked. Her tone was unusually sharp.

"I may have accidentally said yes?"

For a moment, Reina stared at Kumiko and Kumiko stared at Reina. The black-haired girl was astounded; how does one "accidentally" say yes? And to a date, no less?

Reina could feel fury pumping through her.

"Kumiko." Reina's tone was very even, but there was an underlying rage underneath her voice.

"Y-yes?"

"I'm going to kill you."

Kumiko's face blanched instantly. "W-what?" She stammered.

"I'm going to kill you," Reina repeated, her expression very serious. "You broke your promise."

"W-wait, Reina! What are you talking abo—"

But Reina was no longer listening to what Kumiko had to say. With a huff and a rather dramatic turn on her heel, the black-haired girl stormed off. She paid no attention to the calls behind her back.

 _I promise not to abandon you, she said,_ Reina thought, _If I ever break my promise you can kill me, she said._ Reina clenched her teeth together, her pride not allowing her fury to sound itself. _Even if the world goes against you I'll still be by your side, she said._ Reina swallowed, trying to get something to soothe the dryness of her throat, but it did nothing to help. A barely-restrained tear slipped out of her eye and down her cheek. She quickly wiped it away with the back of her hand before anyone could notice.

"She's a horrible person," Reina told herself, voice cracking.

And this time she didn't mean it as a compliment.

-x-

Kumiko was in a state of shock for the rest of the day.

Who wouldn't be, especially since Reina threatened to kill her?

At first, Kumiko didn't get it. But then she remembered a certain promise she told the black-haired girl before the concert.

" _If I ever betray you, you can kill me."_

It dumbfounded Kumiko—surprisingly—that she actually had the audacity to forget such a courageous vow, especially to someone she held special feelings for.

"Oh God, now I have sort _this_ problem out with the others…." Kumiko groaned loudly, slapping herself on the forehead. _But,_ she asked herself, _which one takes priority over the others?_

Kumiko instantly answered, _Reina._ After all, Reina was the one she had feelings for. Why else would she make such a stupid promise?

 _But what about Shuuichi?_

While yes, Shuuichi wasn't necessarily the one she had feelings for, Kumiko still respected him quite a lot (despite that nasty tension that happened in the beginning of the year when he still hadn't apologized for calling her ugly). However, she didn't say yes just because of that—it was a stupid thing, really. Kumiko could feel her previous stupidity coming back in full force. She slapped her cheeks with both hands.

"Augh, how do I tell him I only said yes because I thought he was asking me if I liked beans?!" Kumiko slapped her face again, this time a little harder. She could feel the sting beginning to settle in on her face. "And how do I deal with Reina?" Kumiko gave a loud sigh, her mood slowly deflating with every passing moment.

"What are we going to do?" She asked her euphonium, patting the place where the dent was.

"Talking to inanimate objects again, are we?"

Kumiko jumped in the air and spun around, her hand knocking over her euphonium again. This time, however, she caught it just before it hit the ground. She let out the breath that was stuck in her throat before glaring at the green-haired boy in front of her.

"Shuuichi! What do you want?"

Shuuichi gave Kumiko a frown, one that was deeper than his usual. "Is that how you greet your date for tonight?"

The brunette gave out a groan then turned in circles, exasperated. Shuuichi just stared on with confusion.

"So," he scratched the back of his neck as his cheeks turned a subtle pink, "about later—"

"Shuuichi, listen," Kumiko interrupted him, "about tonight—"

"Yeah, I was just going to discuss that—"

"No!" Kumiko shook her head vigorously, unable to understand why people were so keen on interrupting each other today. "What I mean to say is—"

"Wait, what?" Shuuichi blinked confusedly and then raised an eyebrow, "what do you mean—"

"Shuuichi, I don't like you!" Kumiko bellowed, her fists and eyes closed tightly. She could _feel_ the shock and tension in the air. _Oh, how did it come to this? s_ he wondered to herself.

"B-but you said…?" There was a tremor in Shuuichi's voice, and Kumiko could hardly bear to hear it. Although she didn't share his feelings, she still regarded him as a very close friend. Nothing is more painful, Kumiko believed, than to hurt someone so close to you.

"I know what I said," the brunette opened her eyes and looked up. Shuuichi's eyes had lost their gleam. "But—"

"Did you think it was a joke?" His voice low and his tone was hurt. Kumiko began to sweat; this was spiraling out of control for her.

"N-no! I just—"

"Just what—"

"LET ME FINISH, DAMMIT!"

Shuuichi shut his mouth.

With a sigh, Kumiko ran her hand through her bangs. "I didn't mean to say yes. Because, I...I thought…." The brunette bit her lip and looked away. Embarrassment was overtaking her ability to speak clearly.

"You thought?" Shuuichi probed.

"I thought you were asking if I liked beans."

For a whole second Shuuichi stared at her with the blankest expression Kumiko had ever seen on a person. Then, he quickly doubled-over with laughter, tears coming out the edges of his eyes. Kumiko felt the sudden urge to punch him in the face.

"O-oh God," Shuuichi gasped, unable to find his breath as he wiped a tear from his eyes, "y-you're such an idiot."

"I don't want to hear that from _you._ "

"B-but," he let out another howl of laughter before straightening up, his goofy grin slowly disappearing from his face, "but that's why I like you." A more sincere smile came around, but Kumiko could see the somberness in his eyes. Something about seeing the aloof Shuuichi Tsukamoto like this made Kumiko uneasy. "You'll always be honest, one way or another."

The brunette shook her head.

"I'm...I'm sorry, Shuuichi."

"I know." He gave out a sigh then looked away. He reached up to scratch the back of his neck. "You probably like someone else, huh?"

Kumiko hesitated.

"...I do."

"Who is it?" Shuuichi asked, far too quickly.

"Does it matter?"

The trombonist shrugged. "I guess it does."

"Reina."

Shuuichi turned to look at her with wide eyes.

"W-wait, Reina? As in the trumpet player?"

Kumiko nodded.

"Like, Reina _Kousaka_ right? As in _the_ trumpet player?"

Kumiko frowned.

"There's only one trumpet player that we know named Reina Kousaka, Shuuichi."

The green-haired boy scratched his cheek, uncertainty on his face.

"But...why is it, you know?"

"A girl?" Kumiko finished.

There was an awkward silence as Shuuichi looked away then back. He gave a faint nod of his head.

"Well yeah...but why is it... _her?_ "

"Why not?" Kumiko countered.

Shuuichi just gave Kumiko a blank stare.

"You're weird, you know?"

The brunette gave her friend a soft smile.

"And I'm a terrible person too."

-x-

Reina was mad. She felt betrayed, hurt, and a plethora of other emotions. Even the place she found solace in—the cliff that overlooked the entire town—was a memoir of Kumiko. Reina held her trumpet tightly in her shaking hands. Tears burned the back of her eyes, but her pride held them back.

"Fool," she told herself through gritted teeth, "I'm a fool to think she could understand how I feel—"

"Reina?"

"She's a horrible person," Reina continued, her knuckles turning white as she tightened her grip on her trumpet. "How can I deal with such a—"

"Reina!"

The black-haired girl stopped her rant abruptly. She did not turn around, but Reina knew who was behind her. She refused to look; her pride was not allowing her to.

"Reina…?"

Reina did not move.

"Reina, don't be like this."

Regardless of the other person's pleas, Reina ignored them.

"Reina, come on…."

 _No._

"It's me, Kumiko."

 _I know it's you, you idiot._

"Talk to me, Reina."

 _No._

"Are you upset?"

 _No._

"Is it because Shuuichi asked me out and I accidentally said yes?"

 _...No._

A pair of warm arms wrapped around Reina's waist. The black-haired girl tensed up, forcing herself to not melt into the body she knew was behind her. She had to be cold. She had to hurt her the same way.

"Reina?" Kumiko nudged closer so that her lips barely grazed the trumpet player's ear. Reina tried to ignore the warm breath buffeting her.

"Do you like me?" The brunette asked, her voice barely above a whisper.

Reina closed her eyes.

"Because I really like you," Kumiko added very quietly.

Reina felt time stop. Her brain was unable to process what she had been told, the cars below were nothing but drones, and her lungs forgot how to function. She stood still, very still. She did not sway when the wind blew between them. She did not flinch when Kumiko hugged her tighter for more warmth.

Everything about her stayed still except for her heart.

Soon, everything began to run forward. The blood rushed to her face, her head felt light, and her body was tingling. She finally sucked in a breath, taking a lungful of Kumiko's comforting scent, her heart pounding all the while.

"Do you really like me?" Reina found herself asking. Despite the obvious signs, she was having a hard time believing the brunette. It was too good to be true.

"Yes," Kumiko replied, burying her face in the crook of Reina's neck, "I really, really like you. Even though you love Taki-sensei, I still like you. A lot."

The black-haired girl felt a sting in her chest as Kumiko mentioned Taki-sensei. "My love for Taki-sensei is different," she began, "I look up to Taki-sensei. I admire him. I love him because of his skill and his determination. Those are the feelings of love I hold for him."

Kumiko said nothing, but Reina could feel the brunette nod.

"Those feelings of love, however," Reina took a pause to sort through the words in her jumbled mind, "cannot compare to the ones I feel for you."

The brunette made a little choking sound. "Y-you what?"

Reina frowned. "You just want to hear it again, don't you?"

Kumiko let out a titter. "Y-yeah, kinda. It feels nice to hear."

The trumpeter sighed then turned around in Kumiko's arms. The sight that she saw made her hold her breath.

Kumiko's hair was frizzled as usual, but her askew bangs framed her face _just_ right. Her light-brown eyes, a shade that reminded Reina of caramel, twinkled. Her lips were parted ever so slightly, and only then did Reina notice how close they were. They shared the same breath, inhaling and exhaling at the same time.

Reina was absolutely entranced.

"I—"

"You?"

"I love you," Reina declared with her voice barely above a whisper. Then, with sudden urgency, she closed the distance between them.

The kiss was clumsy and far from perfection, but that didn't stop explosions in Reina's head. Her heart swelled like a crescendo, her pulse skittered like staccatos, and the world around her slowed down to largo.

But just like any piece of music, the kiss ended and they pulled back for a breath.

Reina just had to admire the dorky grin splitting Kumiko's flushed face.

"I love you too," Kumiko replied.


End file.
